Over the past 40 years, it has been found that the application of weak non-thermal electromagnetic fields (“EMF”) can result in physiologically meaningful in vivo and in vitro bioeffects. Time-varying electromagnetic fields, comprising PEMF or PRF, ranging from several Hertz to about 100 GHz, have been found to be clinically beneficial when used as a therapy for reducing pain levels for patients undergoing surgical procedures, promoting healing in patients with chronic wounds or bone fractures, and reducing inflammation or edema in injuries (e.g. sprains).
Although PEMF/PRF therapy has been used for a variety of treatments, one challenge has been in providing a PEMF/PRF delivery device in a design configuration that accommodates the patient's injury and concurrent treatment. For example, EMF devices are difficult to use with patients who are bed-ridden, bandaged, and engaged in ongoing treatment (or monitoring) by metal-containing devices. Some embodiments of present invention provide for configurations of EMF delivery devices that can accommodate such situations where access to the injured area is limited.
Multiple sclerosis (MS) is a frequent and disabling neurological disease characterized by multifocal destruction of central nervous system myelin. The prevalence of MS in Europe is approximately 1/2000 inhabitants. The disease typically begins between the ages of 20 and 30 and affects twice as many women as men. In 80% of cases, the disease initially evolves through attacks which result completely or with sequelae in a few weeks or months (pure remitting phase or emitting phase with sequelae). However, in 40% to 70% of cases, patients who experience an initially remitting evolvement subsequently evolve towards a progressive form (secondary progressive form). In 20% of patients, the evolvement is immediately progressive without attacks (primary progressive form).
For patients who experience an evolvement via regressive attacks, the remissions are less complete over time, resulting in functional sequelae, the ability to walk being lost on average 20 years after the beginning of the disease. Thus, the conventional form of multiple sclerosis can have three evolutive modes: Relapsing-remitting form, Primary progressive form, and Secondary progressive form. The relapsing-remitting form includes exacerbations alternating with remissions during which partial or total recovery is observed. The remissions can last months or years. The exacerbations can occur spontaneously or be triggered by certain external factors, such as an infection, post-partum or certain vaccinations. In the primary progressive form, the disease evolves progressively without remissions, with the possibility of evolutive plateau during which the disease does not progress. Contrary to the cyclic tendency, there are no clear exacerbations. In the secondary progressive form, the disorder follows on from a remitting form which begins with attacks alternating with remissions, followed by a gradual progression of the disease without identifiable attacks. Pyramidal syndrome marks the beginning of (reveals) the disease in 20% of cases, and manifests itself through walking problems with high fatigability, spasticity, exaggerated reflexes in the lower limbs. At the end of the attack, the Babinski sign often remains as a sequela.
Retrobulbar optic neuritis is also an indication of the disease in close to a third of cases: it is the most evocative symptom. It manifests itself for the patient through a rapid and profound decrease in visual acuity, ocular and orbital pain, increased with eye movements, central or cecocentral scotoma and colour blindness (dyschromatopsa of the red-green axis). At the acute stage, the back of the eye is normal, and it is only after about 15 days that atrophy of the papilla occurs, testifying to the damage to the optic nerve and sometimes persistent as a sequela. The visual evoked potentials are impaired, with slowing of the P100 wave.
Sensory problems are common. They are essentially subjective: paresthesia, pins and needles, Lhermitte's sign (electric shock sensation running down the spine when flexing the neck). A posterior cordonal syndrome with deep sensory disorders is sometimes found, and more rarely involvement of the spinothalamic tract with thermalgesic anesthesia. Facial pain (or, conversely, anesthesia) is possible in the event of the trigeminal nerve being affected in its bulbar portion.
The disease may also manifest itself through: a vestibular syndrome combining rotary vertigo, nystagmus and ataxia; a cerebellar syndrome, in which demyelinated plaques are frequent in the cerebellum and in the posterior fossa, which can produce a cerebellar syndrome with an unstable upright stance, walking as if inebriated, movements which are uncoordinated, etc.; diplopia consisting of a sensation of double vision due to paralysis of one or more oculomotor muscles (internuclear ophthalmoplegia is possible in the event of involvement of the posterior longitudinal bundles, which manifests itself in the lateral gaze through an incomplete adduction of one eye associated with nystagmus of the eye in abduction); genito-sphincteric disorders are frequent and are linked to spinal cord involvement, which manifest themselves through urinary urgency (or urinary retention), constipation and impotence. These disorders are a source of acute urine retention, and urinary infections; facial paralysis; and asthenia (fatigue), a frequent symptom of multiple sclerosis, is sometimes the one which is the most debilitating.
Multiple sclerosis is generally considered to be an autoimmune disease which occurs on a particular genetic background. From the neuropathological point of view, the disease is characterized by demyelinated plaques, well-defined hypocellular regions, within which are observed a scarcity of myelin, an astrocytic gliosis and sometimes an inflammatory infiltrate which, when it is present, attests to the active nature of the disease. With time (but sometimes early on), there are also irreversible axonal lesions, the mechanism of which is poorly understood.
Thus, it is possible to distinguish two components in the physiopathology of multiple sclerosis: (1) an inflammatory component, responsible for the evolutive attacks, and beginning with the arrival of CD4+ T lymphocytes in the central nervous system (Weiner, 2004), and (2) a degenerative component, the mechanism of which is for the moment poorly understood (Chaudhuri et al., 2004) and characterized by progression with few inflammation.
Currently, MS and its associated symptoms and pathologies are treated primarily pharmacologically. However, not all subjects respond, or are capable of responding to these therapies, or of withstanding associated side effects of such agents. Thus, there is a need for other therapies, and in particular non-invasive and/or not pharmacologic therapies.
While EMF treatments have been explored for a variety of uses, the possible benefits of EMF in treating or preventing neurological injury and degenerative conditions such as MS and related conditions are relatively unknown. This is in part due to the fact that the inflammatory response in the central nervous system (CNS) differs somewhat from that of the periphery systems for which EMF signals are currently used.
Described herein are methods and apparatuses that may address the needs and concerns described above.